Cosby guilty of drugging, molesting woman

US entertainer Bill Cosby has been found guilty in a retrial on three counts of sexual assault

Bill Cosby has been convicted of drugging and molesting a woman in the first big celebrity trial of the (hash)MeToo era.

It completes the spectacular late-life downfall of a comedian who broke racial barriers in Hollywood on his way to TV superstardom as America's Dad.

Cosby, 80, could end up spending his final years in prison after a jury concluded he sexually assaulted Temple University employee Andrea Constand at his suburban Philadelphia home in 2004. He claimed the encounter was consensual.

Cosby stared straight ahead as the verdict was read on Thursday but moments later lashed out loudly at District Attorney Kevin Steele after the prosecutor demanded the former TV star be sent immediately to jail. Steele told the judge Cosby has a plane and might flee.

"He doesn't have a plane, you a**hole!" Cosby shouted at Steele. "I'm sick of him!"

The judge decided Cosby can remain free on $US1 million bail while he awaits sentencing, but restricted him to Montgomery County, where his home is. No sentencing date was set.

Cosby waved to the crowd outside the courthouse, got into an SUV and left without comment. His lawyer Tom Mesereau declared "the fight is not over" and said he will appeal.

Shrieks erupted in the courtroom when the verdict was announced, and some of his accusers whimpered and cried. Constand remained stoic, then hugged her lawyer and members of the prosecution team.

"Justice has been done!" celebrity lawyer Gloria Allred, who represented some of Cosby's accusers, said on the courthouse steps. "We are so happy that finally we can say women are believed."

The verdict came after a two-week retrial in which prosecutors put five other women on the stand who testified that Cosby, married for 54 years, drugged and violated them, too. One of those women asked him through her tears, "You remember, don't you, Mr Cosby?"

The panel of seven men and five women reached a verdict after deliberating for 14 hours over two days, vindicating prosecutors' decision to retry Cosby after his first trial ended with a hung jury less than a year ago.

Constand, 45, a former Temple women's basketball administrator, told jurors that Cosby knocked her out with three blue pills he called "your friends" and then penetrated her with his fingers as she lay immobilised, unable to resist or say no.

It was the only criminal case to arise from a barrage of allegations from more than 60 women who said the former TV star drugged and molested them over a span of five decades.

Cosby's retrial took place against the backdrop of (hash)MeToo, the movement against sexual misconduct that has taken down powerful men in rapid succession, among them Harvey Weinstein, Matt Lauer, Kevin Spacey and Senator Al Franken.

Cosby's lawyers slammed (hash)MeToo, calling Cosby its victim and likening it to a witch hunt or a lynching.

Cosby's new defence team, led by Mesereau, the celebrity lawyer who won an acquittal for Michael Jackson on child-molestation charges, launched a highly aggressive attack on Constand and the other witnesses.

Their star witness, a longtime Temple employee, testified that Constand once spoke of setting up a prominent person and suing. Constand sued Cosby after prosecutors initially declined to file charges, settling with him for nearly $US3.4 million over a decade ago.

But Cosby himself had long ago confirmed sordid revelations about drugs and extramarital sex.

In a deposition he gave over a decade ago as part of Constand's lawsuit, Cosby acknowledged he had obtained quaaludes to give to women he wanted to have sex with, "the same as a person would say, 'Have a drink'."

Cosby also acknowledged giving pills to Constand before their sexual encounter. But he identified them as the over-the-counter cold and allergy medicine Benadryl and insisted they were meant to help her relax.